Photographic emulsions containing novel fog-inhibiting addenda



United States Patent 3,157,599 PHGTUGRAPHLC, EMULSiGNS QSNTAlNlNG N GVEL FOG-INHlBlTlNG ADDENDA Jean E. Jones, Rochester, N.Y., assigner to Eastman Kodak Company, Rochester, NY a corporation of New lersey N Brewing. Filed Mar. 2%, 1962, Ser. No. 131,153+ 1'7 Claim. (Cl. 96tl9) This invention relates to stabilized photographic compositions, and more particularly, to photographic silver halide emulsions containing novel fog-inhibiting agents.

It is well-known that photographic emulsions on storage tend to lose sensitivity and to become spontaneously developable without exposure to light. There is normally a detectable amount of the silver salt reduced during development in the areas where no exposure was given, this commonly being called fog, and sometimes chemical fog Where it is necessary to distinguish between it and the effects of accidental exposure to radiatiou. In this invention 1 am not concerned with the latter.

Fog depends both on the emulsion and the conditions of development. Gold and sulfur sensitized emulsions are particularly subject to fogg ng. For a given emulsion, tog increases with the degree of development. With constant development conditions, fog tends to increase with time, temperature and relative humidity of storage conditions. It is common practice to make tests to determine the stability of photographic emulsions by storage at increased temperature or humidity, or both, as such conditions commonly occur in tropical climates, for example. Fog usually appears over the whole area of the sensitive coating, but when severe, it frequently is non-uniform. Fog may also be caused by exposure to chemicals, for example, hydrogen sulfide and other reactive sulfur compounds, hydrogen peroxide vapor, and strong reducing materials. While antifoggants and stabilizers may protect, to some extent, against such effects, it is normally understood that an entifoggant pr0 tects against spontaneous growth of fog during prolonged storage or storage at high temperatures and humidities, or during development to maximum contrast and speed, or both.

It is an object of this invention to inhibit fog fcrma- 4-carbalkoxy-5-alkyl-1,2,3-triazoles, 1,2,3-triazole-4-carboxyaldehyde, 1,2,3-triazole-4-carboxylic acid,

4,5 -dicarboxy-1-hydroxy-1 ,2,3-triazole,

Dialkyl- 1,2,3-triazole-4,S-dicarboxylates, l-phenyl-l,2,3-triazole-4,S-dicarbohydrazlde, or 4,5-dicarboxy-l,2,3-triazole,

0 "ice wherein the alkoxy and alkyl moieties can suitably contain 1 to 20 carbon atoms and are more generally 1 to 4 carbon atoms. Such substituted 1,2,3-triazoles can be prepared by the methods described in Wolff et al., Ann., 325, 153 (i902); JACS, 71, 1436 (1949); JACS, 76, 4935 (1954); J. Pract. Chem, 76, 394 (1907); Berichte, 26, 545, 2737 (1893); J. Pract. Chem., 125, 466, (1930).

The addenda of the invention described above can be added to photographic silver halide emulsions for purposes of increasing the stability thereof. More specifically the subject addenda serve as emulsion antifoggants. Many antifoggant addenda cause substantial desensitization or loss in speed of the emulsion When employed therein in antifoggant amounts. However, with the subject addenda there is no substantial loss of speed imparted to emulsions.

The particular quantity of the present stabilizers used in a given emulsion can vary, depending upon the effects desired, degree of ripening, silver content of the emulsion, etc. I have found that generally from about .001 to 1 3 grams per mole of silver halide are quite adequate to accomplish the desired stabilization. Exposure of treated emulsion in conventional photographic testing apparatus, such as an intensity scale sensitomeer, will reveal the most advantageous concentrations or the present stabilizers in a particular emulsion. Such echniques are Well understood by those skilled in the art.

The addenda of the invention can be added to photographic emulsions using any of the well-known techniques in emulsion making. For example, they can be dissolved in a suitable solvent and added to the silver halide emulsion, or they can be added to the emulsion in the form of a dispersion similar to the technique used to incorporate certain types of color-forming compounds (couplers) in a photographic emulsion. Techniques of this type are described in Jelley et al., U.S. Patent 2,322,027, issued June 15, 1943, and Fierke et al., US. Fatent 2,801,171, issued July 30, 1957. The solvent should be selected so that it has no harmful effect upon the emulsion in accordance with usual practice, and generally solvents or diluents which are miscible with water are to be preferred. Water alone is a dispersing medium for some of the stabilizers oi the invention. In other cases, the subject stabilizers can be dissolved in solvents, such as ethanol, acetone, pyridinne, N,N-dimethlyformamide, etc, and added to the emulsion in this form.

in addition to the subject antifoggant addenda, the photographic emulsions of the invention can contain the usual well-known emulsion addenda such as optical sensitlzers, speed increasing materials, coating aids, gelatin hardeners, plasticizers and the like.

The subject antifoggant addenda have particular utility in sulfur and gold sensitized photographic silver halide emulsions. For example, sulfur compounds such as described in Sheppard, US. Patent 1,574,944, issued March 2, 1926; Sheppard et al., US. Patent 1,623,499, issued April 5, 1927; and Sheppard et al., US. Patent 2,410,689, issued November 5, 1946, can be utilized. The emulsions of the invention can be sensitized with gold salts such as those described in Waller et al., US. Patent 2,399,083, issued April 23, 1946, and Damschroder et al., US. Patent 2,642,351, issued June 16, 1953. Illustrative gold salts include potassium chloroaurite, potassium aurithiocyanate, potassium chloroaurate, auric trichloride, 2-aurosulfobenzothiazole methochloride, and the like.

' Compound D:

' CompoundE:

The stabilizer addenda of the invention can be used in various kinds of photographic emulsions. In addition to being useful in orthochromatic, panchromatic, and infrared sensitive emulsions, they are also useful in X-ray and other non-optically sensitized emulsions. added to the emulsion before or after any opticfl sensitizing dyes which may be used. Various silver salts can be used as the sensitive salt such as silver bromide, silver iodide, silver chloride, or mixed silver halides such; as silver chlorobromide or silver bromoiodide. The subject addenda can be used in emulsions intended for color photography, for example, emulsions containing colorforming couplers or emulsions to be developed by solutions containing couplers or other color-generating materials.

Inthe preparation of the silver halide dispersions employed for preparing silver halide emulsions, there can be employed as the dispersing agent for the silver halide in its preparation, gelatin or some other colloidalrnaterial such as colloidal albumin, a cellulose derivative, or a synthetic resin, for instance, a polyvinyl compound, although gelatin is preferred.

The above-described emulsions of the invention can be coated on a wide variety of supports in accordance with usual practice. Typical supports for photographic elements of the invention include cellulose nitrate film, cellulose acetate film, polyvinyl acetal film, polystyrene film, polyethylene terephthalate film, and related films of resinous materials, as well 'as glass, paper, metals, W004i,

and others.

Several substituted 1,2,3-triazolesor" the invention were prepared and incorporated into photographic silverhalide emulsions at varying concentrations and thereafter tested as antifoggants. The structural formulas of these prepared addenda of the invention are. lettered and listed below, the letters given the addenda below being used for purposes of convenience of reference to indicate these addenda in the tables of Examples 1 and 2 below. Compound A:

CH C=N ll 011 01120 oo=N 4-carbeth0xy-5-methyLl,2,3 triazo1e Compound B:

-' HCT=N NH 110-. :N 1,2,3-triazole--carboxaldehyde Compound C: I

HO=N

O NH HOG-:31 1,2,3-triaz01e-4-carboxy1ic acid ii HO CCHN-OH O NH ll 7 n o c-o n 4,5-dicarb0xy 1 hydroXy-l,2,3-triazole 01330 CC=N i 0 H3 0 ZN V Dimethy1-1,2,3-triazole-d,Edicarboxylate Compound F:

They can be a EXAMPLE 1 Typical substituted 1,2,3-triazole stabilizers of the ink vention were incorporated into sulfur and gold sensitized high speed negative-type gelatino-silver bromoiodide emulsions that'were panchromatically sensitized 'with a cyanine dye, and thereafter the emulsions were coated on cellulose acetate film supports. Similar photographic elements were prepared without the feature stabilizers addenda for purposes of comparison. Samples of the prepared photographic elementswere packaged at 72 F. and 50% relative humidity in vapor proof containers, incubated for 7 days at 120 F. and then exposed in the form of filrnstrips in an Eastman 1B Sensitometer to light of daylight quality modulated through a step wedge for second, developed for 5' minutes at 68 F., and then fixed, washed and dried in the usuai'manner. Test samples were also exposed in the sensitometer directly after coating for purposes of comparison. The developer had the following formula:

G.. N-methyl-p-aminophenol sulfate 1 2.5 Hydroquinone 2.5 Sodium sulfite (anhydrous) 30.0 Sodium metaborate octahydrate 10.0

Potassium bromide a 0.5 Water to make 1 liter. 7

Table A Cone. of Initial test 7 Days at 120 F. Addenda Addenda (gJrnole V of AgX) Speed 7 Fog Speed 7 Fog Control. 0 v 1. 23 14 '102 1; 17 39 Compound .A 1. 5 81 1. 30 12 98 1. 25 .16- Compound 13.. 1.5 98 1. 25 13 115 1.12 18 instance, and which. speed loss characterizes manyantifoggants and many other emulsion addenda. j

EXAMPLE 2 Photographic gelatino-silverbromoiodide emulsions as described in Example 1 were prepared with other addenda of the invention and thereafter tested as described in Example 1- except that a 14-day incubation period wasutilized in lieu of the 7-day incubation period; The results are summarized by the da ta set out in Table B below,

Table B Cone. of Initial test 14 Days at 120 F. Addenda Addenda (gJmole of AgX) Speed 7 Fog Speed 7 Fog Control 100 1. 15 13 59 93 39 Compound E- 1. 112 1. 27 12 107 1 02 18 Do 3. 0 107 1. 23 12 99 1 00 15 Control 0 100 1. 05 74 97 54 Compound F- 3.0 100 1. 08 09 96 90 29 D0 6.0 105 1.08 0% 98 93 27 Compound G 3.0 130 1. 10 09 115 1 00 19 o 6.0 115 1. 00 10 112 1 02 17 The data set out in Table B further illustrates the im proved stability of the emulsion of the invention.

EXAMPLE 3 Table C Cone. of Initial test Addenda (gJmole of AgX) Soeed 14 Days at 120 F. Addenda Control-.-" Compound Y- Do Compound Z Do As can be observed from the data set out in Table C, Compounds X, Y, and Z, while being closely related to the antifoggant addenda of the invention are not useful antifoggants. Other substituted 1,2,3-triazoles that were tested as described in Examples 1 and 2 and were found to lack the good antifoggant properties possessed by the addenda of the invention included:

1,2,3-triazole-4-carbohydrazide,

1-benzyl-1,2,3 -triazole-4,S-dicarboxamide, 4,S-dicarboxy-l-phenyl-1,2,3-triazole, Dimethyl-l-phenyl-l,2,3-triazole-4,S-dicarboxylate, and 4-carboxy-2-phenyl-1,2,3-triazole.

The invention thus provides a new and useful class of photographic silver halide emulsion antifoggant addenda.

The invention has been described in considerable detail with particular reference to preferred embodiments thereof, but it will be understood that variations and modifications can be efiected within the spirit and scope of the invention as described hereinabove and as defined in the appended claims.

I claim:

1. A photographic silver halide emulsion containing an 6 antiioggant amount of a substituted 1,2,3-triazole selected from the group consisting of a 4-carbalkoxy-5-alkyl-1,2,3-triazole, 1,2,3-triazole-4-carboxaldehyde, 1,2,3-triazole-4-carboxylic acid, 4,5-dicarboXy-l-hydIoxy-1,2,3-triazole,

a dialkyl-l,2,3-triazole-4,'5-dicarboxylate, 1-phenyl-1,2,3-triazole-4,S-dicarbohydrazide, and 4,S-dicarboxy-1,2,3-triazole.

2. A photographic silver halide emulsion containing an antifoggant amount of a 4-carbalkoXy-5-alkyl-l,2,3-triazole wherein the alkoxy and alkyl moieties have 1 to 4 carbon atoms.

3. A photographic silver halide emulsion containing an antifoggant amount of 1,2,3-triazole-4-carboxaldehyde.

4. A photographic silver halide emulsion containing an antifoggant amount of 1,2,3-triazole-4-carboxylic acid.

5. A photographic silver halide emulsion containing an antifoggant amount of a dialkyl-1,2,3-triazole-4,5-dicarboxylate wherein the alkyl moieties contain 1 to 4 carbon atoms.

6. A photographic silver halide emulsion containing an antifoggant amount of 4,5-dicarboxyl-1-hydroxy-1,2,3- triazole.

7. A photographic silver halide emulsion containing an antifoggant amount of l-phenyl-l,2,3-triazole4,5-dicarbohydrazide.

8. A photographic silver halide emulsion containing an antiioggant amount of 4,5-dicarboxy-1,2,3-triazole.

9. A photographic gelatino-silver halide emulsion con taining about .001 to 10 grams per mole of silver halide in said emulsion of 4-carbethoxy-5-methyl-1,2,3-triazole.

10. A photographic gelatino-silver halide emulsion containing about .001 to 10 grams per mole of silver halide in said emulsion of 1,2,3-triazole-4-carboxaldehyde.

11. A photographic gelatino-silver halide emulsion containing about .001 to 10 grams per mole of silver halide in said emulsion of 1,2,3-triazole-4-carboxylic acid.

12. A photographic gelatino-silver halide emulsion containing about .001 to 10 grams per mole of silver halide in said emulsion of 4,5-dicarboxy-1-hydroxy-1,2,3- triazole.

13. A photographic gelatino-silver halide emulsion containing about .001 to 10 grams per mole of silver halide in said emulsion of dimethyl-1,2,3-triazo1e-4,5- dicarboxylate.

14. A photographic gelatino-silver halide emulsion containing about .001 to 10 grams per mole of silver halide in said emulsion of l-phenyl-l,2,3-triazole-4,5- dicarbohydrazide.

15. A photographic gelatino-silver halide emulsion containing about .001 to 10 grams per mole of silver halide in said emulsion of 4,5-dicarboxy-1,2,3-triazole.

16. A photographic emulsion support having coated thereon an emulsion as described in claim 1.

17. A photographic silver halide emulsion as described in claim 1 wherein the emulsion is gold and sulfur sensitized.

OTHER REFERENCES Kuwabara et al.: Chemical Abstracts, vol. 51, pages 16159- (1957). 

1. A PHOTOGRAPHIC SILVER HALIDE EMULSION CONTAINING AN ANTIFOGGANT AMOUNT OF A SUBSTITUTED 1,2,3-TRIAZOLE SELECTED FROM THE GROUP CONSISTING OF 